Fuel supply chamber



July 22, 1941. s. M. UDALE FUEL SUPPLY CHAMBER Filed June 17. 1939 2Sheets-Sheet 1 INVENIOR.

s. M. UDALE 2,249,992

FUEL SUPPLY CHAMBER July 22, 1941.

2 Sheets-Sheet 2 Filed June 17. 1939 diaphragm chamber 4 l PatentedUNITED STATES PATENT OFFICE runnsurrnrcnamnnn Stanley M4 none, Detroit,Mich, auignor to GcorgeMHolleyandEarlHolley- V Application 1 11, 1939,Serial No. 279,643 1 Claim- .(ci. 261-72) v i In the ordinary floatchamber of a carburetor,

the gases are automatically removed, either by v p the provision of apassage leading from the space above the level of the liquid in'themixture out let, or of a passage leading to the air entrance. When thefuel is supplied in a diaphragm chamber, all the liquid which passesinto the diaphragm chamber must pass out, together with any vaporentrained with the liquid. As the liquid enters thediaphragm chamber,there is a drop in pressure of approximately seven pounds per squareinch. This drop in pressure releases small quantities of vapor which mayaccumulate and cause irregular running. In the applicants construction,this vapor is automatically removed at all times and the vapor isremoved independently of the discharge of the liquid'from the chamber.By this means, the metering characteristics of the carburetor are notinterfered with shown in the Patent 2.088,464, issued to Chandler andKittler.

In the drawings:

Figure 1 illustrates diagrammatically the in vention.

Figure 2 shows the detail of the actual construction used.

Figure v3 shows a plan view on the plane 3-3 of Figure 2.

In Figure 1, in the air entrance I is located a bridge II in whichslides a needle valve l2, which controls the discharge of the fuel fromthe This needle valve I2 is operated by a lever I3 which carries aroller H which engages with the cam l5 keyed to a shaft I 6.

Three gears II, It and I9 intermesh with each other. The gear I1 ismounted on the shaft It; the gear l8 ismounted on the throttle 2|, andthe gear I9 is mounted on the throttle 20. These two throttles 20 and 2|approach and recede from the bridge 22 which is streamlined. The openingbetween the bridge 22 and the throttles 20, 2| thus constitute variableventuri passages.

The fuel controlled by the needle valve [2 discharges through theopenings 23, 24 into the air is supplied from the annular passage 28which communicates with the air entrance ll.

throat of the venturls and discharges on the engine side of the throatof the vcnturis formed between the throttle valves 2!, 2| and the bridge22. The fuel flows past the restriction II and down the passage 25. VThis fuel is mixed with a small quantity of air drawn through theopening 28, and-when the throttles are closed (during the time that theengine is idling) by another small quantity otair' admitted through theopening 21 in the center of the needle valve II. This through an opening2|. The fuel, which is metered between the restriction II and the needlel2, flow through the passage 4. and is obtained from the lower part-ofthe diaphragm ll through the tube 48. The diaphragm chamber ll isformedby the two diaphragms 42 and 43 held together by thespring 44. Thesediaphragms control the needle valves 88, N which are pivoted at 6|.- 62and control the'fuel entrance from the passage 40. a

The fuel is supplied to the fuel chamber ll under a substantialpressure, but the leverage is such and the diaphragms are so large, andthe needle valves N, I! are so small, that the presknown airplanecarburetor. The means for the removal of the vapor are as follows! Afloat 5| pivoted at 52 is located in the upper part of the diaphragmchamber 4| and controls a valve 53 which closes the entrance to thehorizontal pas,- sage 54 which terminates in the passage IS in thethroat of the variable ventur'i formed between the throttles 2. and thebridge 22.

Operation When the engine is running, vapor accumulates in the upperpart of the diaphragm chamber 4| and displaces a certain quantity ofliquid. The float 5| descends and in doing so, opens the valve 53. Theupper part of the chamberj ll is then subjected to the suction in thethroat of the variable venturi. Before any liquid can flow through thepassage 54 the float 5| rises and closes the needle-valve 53. The levelof fuel in the chamber 41 is thus maintained at the level shown by thebroken lines through the center of the float 5|.

In Figures 2 and 3, similar numbers refer to similar parts. For example,the diaphragm 42 operates the lever pivoted at 62, the lever pivoted at6| being operated by the diaphragm 43. Instead of a needle valve, ballvalves 63, N are used. The float ii is located in a chamber on the sideof the main body of the carburetor and the needle II is locatedcentrally of the float ii. The vapor is drawn through a pipe 54 to anoutlet 55 located in the mixture outlet rather than in the throat of thevariable venturi. As the float is not located in the highest part of thediaphragm chamber, it is necessary to provide a passage so that thevapor is drawn from thehighest point in the diaphragm chamber. I

What I claim is:

In combination with a carburetor having a 20 mixing chamber, a throttlevalve, a mixture outlet and a normally closed fuel supply chambercontrolled by a movable wall, a fuel mechanism adapted to limit the headof fuel in said chamber, a fuel discharge passage having an entrancelocated substantially at the center of said supply chamber, a vaporoutlet leading out of the upper portion of said chamber, both of saidpas-

